Synchronizing clutch



Patented May 26, 193.6

sYNcnnoNizlNG CLUTCH Leon Jay Campbell, Buchanan, Mich., assignor to Campbell-Buchanan Corporation, Chicago, Ill., a corporation of Illinois Application December 27, 1932, Serial No. 648,899

trol quickly and smoothly without shock or noise.

Another object of my invention is to provide the co-acting inclined surfaces of these clutch members with concentric portions of different diameters whereby the desired slippage or relative rotation may be permitted between the members in establishing a synchronizing driving connection between them.

A further object of my invention is to provide the clutch members with means on their co-acting surfaces to break down the film of oil or lubriA cant between them whereby the clutch members may quickly engage for driving action.

A further object of my invention is to provide at least one of these surfaces with grooves or slots to receive and carry off the oil or lubricant re'- moved or scraped therefrom in the relative rotation of the members while pressed together to condition the surfaces for frictional drivingr ngagement. The invention consists further in the matters hereinafter described and claimed.

In the accompanying drawing: Fig. 1 is a longitudinal section of a clutch assembly of my invention, the synchronizing members of the clutch being shown in frictional driving engagement; l Fig. 2 is a transverse sectional View taken on line 2-2 of Fig. 1;

Fig. 3 is a view similar to Fig. 1 showing the 4o synchronizing clutch members in positive driving engagement;

Fig. 4 is a transverse sectional view taken on line 4 4 of Fig. 3; and

Figs. 5 and 6 .are perspective views on a reduced scale ofthe synchronizing clutchmembers in completely separated relation. y l

In the drawings, I, 2 indicate the alined driving and driven shafts of an automotive change speed transmission of a type in general use.

Shaft I. leads from the master clutch ofthe vehicle and has within' the transmission case a. gear 3,V integral with the shaft as shown in Figs. 1 andif and meshing with a lay shaft gear (not shown) as in devices of this character. The end of the shaft I at the gear 3 is made hollow and is fitted with a wear bushing 4 to receive and support the adjacent reduced end 5 of the shaft 2- as shown.

The portion of the shaft I beyond the inner side of the gear 3 is provided with splines 6. The pores tion of shaft 2 beyond the adjacent end of shaft I is provided with si'milar's'plines 1. The splined portions of the shafts have the same diameter` and with the splines similar they will register when the shafts are synchronizedl When that 10 occurs, the clutch member B on the shaft I may be slid onto shaft 2 to connect the shafts for direct driving as requiredforshigh speed in an automotive transmission. f

Clutch member B/is in the form of a ring sur- 15 rounding the shafts and has internal teethQ to mesh with those provided by the splines 6 and 1. Member 8 is not completely withdrawn from shaft I when connecting shaft 2 thereto, on the contrary, being merely slid partially onto shaft 2 20 to bridge the joint between the abutting or adjacent ends of the shafts and thus have connection with the splines of both shafts'. Normally member 8 is entirely supported by shaft I, at which time the shafts are disconnected and may 25 be synchronized by the synchronizing clutch members III- and II of my present invention. The member 8 fits -within an annular recess I I a in the member Il and has a rotative connection therewith. The member 8 is maintained inthe 30 recess by means of a split locking ring 8a'overlapping the member 8 on the open side of the recess Ha as shown in Figs. 1 and 3. The ring 8a. is preferably of spring material and snaps into a groove I'Ib in the member II when connecting 35 the members together. A wear ring 8b is intere posed between the member 8 and the locking ring 8a. 'I'his wear ring is preferablykeyed on the member I I. The keying may take the for-m of di-f ametric lugs on thev wearring, which lugs engage 40 in key slots provided in the inner surface of the recess Ila.

Members I0 and II are annular in shape and are mounted onthe respective shafts I and 2 on opposite sides of the positive clutch member 8. 45

Member Ill'ts over thesplined portion of shaft I and. is fixed thereto by lugs I2 .and a split clamping ring I3. The lugs I2 are carried by the member -IIl and t in the spaces between cer- 50 tain of the splines 6 to hold the member against rotation on the shaft I. The lugs proiect beyond the front side of the member I0 and are overlapped by the ring I3. The latter enclrc'zles,l the splines and tightly engaging vv)the sameholds 55 gear 3.

Member II is slidably, but non-rotatably connected with shaft 2 on the splined portion thereof, having internal tee th I4 for that purpose. Member I I is sh'aped to surround member 8, there being a suitable connection between them for movement in unison in an axial direction when member II is shifted laterally by the shifting element or yoke I5 engaged therewith as shown. Member II has an annular recess I6 to receive the yoke, the latter by a spring means, indicated generally at I I in the drawing, being normally pressed in a direction to engage members Ill and II. The spring means does not engage the yoke in the manner shown in Figs. 1 and 3 in an actual installation. It is embodied in the control for the transmission and acts when released to force member II into engagement with member I0.

Member I has an overhanging annular-portion or flange I8 extending toward member I I,

as shown. This flange is lined with a wear resisting ring I9 having a tapered or inclined surface 20 to co-act with a complementary inclined surface 2| about the periphery of member II. The portion of member I I provided with this surface extends into member I0 so that the members fit one within the other when engaged, as shown in Figs. 1 and 3. At this time the shafts I and 2 are disconnected by the positive clutch member 8 and the members I0 and II mayl act to synchronize the shafts as intended by my invention.

The co-operating inclined 'surfaces 2U, 2I of the members I0 and II, in accordance with my invention,1 are provided with arcuate portions of different diameters, permitting frictional driving engagement of the members in certain rotative positions, and positive driving engagement in others. This is accomplished by providing the member vII with diametrically disposed arcuate sections 22, 22- of one diameter and lthe intermediate joining sections 23, 23 of a slightly lesser diameter. Where these sections join, well defined edges 24 are formed, as shown in Fig. 5.

The inclined surface 20 of the member I 0 is similarly made, the arcuate sections 25 being of the larger diameter, while the sections 26 are of the smaller, there being edges 21 provided between the sections where they join as shown. The corresponding sections on the two members are complementary throughout as to pitch or angle, diameter and circumferential length, so that the members may completely interiit, as shown in Figs. 3 and 4, when tle members register as to their respective sections. At this time, the sections of the largest and of the smallest diameters on the respective members intert and the members are connected together 'in positive driving engagement.'

When the sections 22 of the largest diameter on member II engage the sections 264 of the .smaller diameter on member I8, the members cannot completely interfitby reason of the difference in the diameters of the engaged sections, as i shown in Figs. 1 and 2. The members I0 and II by the springpressure on them tend to frictionally engage and do so as soon as the oil lm on their engaged surfaces .is broken down by the edges 24, 21. These edges in the relative rotation of the members act 'to scrape the oil film from the inclined surfaces and conditionthem for fr ictional engagement so that the' driving member Will pick up the driven member without shock or noise. The inclined surface 20 of the member I0 is provided with radial grooves jor slots 28 to ,the member III against the inner side of the receive and carry off the 'accumulated oll, the grooves opening through the outer edge of the ring I9, as shown.

Should the frictional engagement between the members when they initially engage, be insumcient to synchronize them, the members Will slip as allowed by their inclined surfaces, and will assume positive driving connection when they reach that relation. This will remain unless the load on the driving member is too great, whereof engagement with the member I0. at the same' time through the yoke I5. It may be remarked at this point, that the back and forth movement given to the yoke I to accomplishthis result, is automatically controlled through the operation of the hand shift lever or other equivalent part by which the speed changes inthe transmission are effected. In my co-pending application, Se-

rial No. 635,957, filed October 3, 1932, which has matured into Patent No. 1,984,354, December 18,

1934, a spring cont-rol is provided for this purpose and may be usedwith the type of clutch assembly herein described and claimed.

Inan automotive transmission two clutch devices as herein shown and described would ordinarily be employed, one for the direct drive asA shown and the other for second or intermediate speed as in my co-pending application as aforesaid. Botn clutch assemblies are alike in construction and operation, except as 'to the reversal of the positions of the parts for second speed.

The advantages of my novel clutch mechanism, as herein shown and described, are that a metal to metal contact is provided between the synchronizing clutch members .I0 and II when they reach driving engagement, both at the time they drive through frictional engagement and when they drive through positive engagement. This enables the load von the driving member to be picked up quickly, yet smoothly and easily, with# out strain or jar on the clutch assembly or associated parts and their synchronization established within the very short range of movement allowed for the purpose in the transmission control.

Moreover, the-oil 4film is broken down shortly' after the clutch members are pressed together, and no opportunity is allowed for the driving member to become so accelerated in speed as to pro'duce a shock and noise when the members engage on their co-acting surfaces becoming sufficiently dry for the purpose. With the arrangement of arcuate sections between the members, they may rapidly engage Aand ,disengage in their relative rotation and thus quickly establish syn- .chronization for the parts 'controlled thereby.

larger diameter.

tively engage more than once in each complete revolution of the members. This follows from the fact that the projections and the recesses provided on the interfltting inclined annular surfaces of the clutch members are substantially equal in circumferential extent and are diametrically and alternately arranged as shown in Fig. 6.

When these parts each comprise approximatelya fourth of thecircumference of their respective clutch members as shown in Fig. 6the clutch members mayfrictionally Aand positively engage twice in each complete revolution of the members. This reduces the extent of rotative slippage between the clutch members before they postively engage and the shock and jar incident to their positive engagement is so reduced as to provide for a smooth and easy acting clutch the projections and the recesses are concentric with that axis. The sides of the projections and the recesses on each-clutch member are joined by inclined portions enabling rotative slippage of the clutch members under a torque strain in excess 'of the holding action of the projections and the recesses when interfltting. Y

As shown in' Figs. 1 and-3, the positive clutch member 8 ts rotatably in the synchronizing clutch member I I to rotate relative thereto, both when on shaft I and when connecting shafts I and 2 together- By a split ring arrangement shown in these figures, the clutch member 8 is connected with the member I I to slide in unison therewith, thereby providing axial movement for the member 8 through the member I I.

The details of construction and arrangement of parts shown and described may be variously It is to be of course understood that the clutch mechanism of my invention as herein shown and described, when installed in an automotive change 'speed transmission, will run in the presence of the lubricant contained in the transmission case, and thus be subject'to the provision of a lubricant film on the members I0 and Il between the 5 co-operating inclined surfaces thereof.

f I claim as my invention: A

1. In a synchronizing clutch mechanism'fcr automotive change speed transmissions, co-oper'- ating synchronizing clutch members, saidv Synl0 chronizing clutch members having interfittin'g inclined portions provided with arcuate sections of different diameters whereby the members incertain rotative positions may have frictional driving engagement and positive driving engage-'15 ment in others, said sections where they join on the respective members providing edges to scrape the lubricant from the co-acting surfaces of the members in their relative rotation, and slots in the surface of one member to receive the lubricant scraped from the members.

2. In combination, aligned driving and driven shafts having their opposed portions closely arranged and similarly splined, a pair of cooper-l ating clutch members on the respective shafts, one clutch member being fixed to the driving shaft for rotation thereby, and the other clutch member being slidably mounted on the driven shaft by engagement with the splines thereof for movement into and out of clutching engagement with the clutch member on the driving shaft, said clutch members having interengageable inclined annular surfaces provided with arcuate projec-l tionsand recessesconcentric with the ax'es of said shafts'whereby said clutch members when 35 engaged may have frictional driving engagement when the peripheral surfaces of the projections are engaged and positive driving engagement vwhen the projections on one clutch member enter the recesses on the otherclutch member, and a 49 third clutch member slidably mounted Ion the driving shaft by engagement with the splines thereof and movable by thev clutch member on the driven shaft into engagement with the splines of the same for positively connecting the shafts by the third clutch member following disengagement of the rst mentioned clutch members on synchronization o f the shafts thereby, said third clutch member having a rotative connection with 50 the clutch member on the driven shaft.

. LEON JAY CAMPBELL. 

